The subject of this patent application relates generally to coffee roasters, and more particularly to a fluid bed coffee roasting system configured for roasting batches of coffee beans of varying sizes—ranging from relatively small profile sizes to relatively large production sizes—without increasing the size of the system, operating costs of the system, or desired roasting times.
Applicant(s) hereby incorporate herein by reference any and all patents and published patent applications cited or referred to in this application.
By way of background, the process of roasting coffee beans commonly involves the use of either a drum roasting system or a fluid bed roasting system. Fluid bed roasting systems use a stream of high velocity air that is heated using electric resistive heating elements, or gas burners fueled by propane or natural gas. This high velocity hot air is used to levitate and roast green coffee beans in a fluidized bath of hot air, allowing uniform roasting of the individual beans. Heat is transferred directly to the mass of green coffee beans via convection through the heated air. This is distinguished from roasting coffee using a drum roasting system which relies primarily on conductive heat transfer through the heated drum wall which the green coffee is tumbled against during the roasting process which, in turn, typically results in a relatively less uniform roast of the individual beans. Additionally, as the coffee beans are levitated in the hot air stream, they roll and tumble in the super-heated air, which causes unwanted by-products of the roast (i.e., burnt chaff, under size or broken beans, etc.) to be expelled by the convective/lifting action of the hot air. However, while fluid bed roasting systems are often capable of producing relatively higher quality coffee beans, they are traditionally limited in the volume of beans that can be roasted in a given batch. Specifically, most traditional fluid bed coffee roasters are capable of roasting no more than 10 to 12 pounds of beans in a given batch. In other words, with traditional fluid bed roasting systems, the only ways to increase the volume of beans in a given batch have been to increase the size, air temperature, and/or air velocity of the fluid bed roasting system (which could potentially render the system too large to fit in a user's facility, or too expensive to operate), or to increase the roasting times (which could potentially over-roast a portion of the beans). Thus, there remains a need for a fluid bed coffee roasting system capable of roasting relatively larger batches of beans without increasing the size of the system, operating costs of the system, or roasting times.
Another recognized issue in the relevant art is in connection with producing sample roasts. Traditionally, commercial coffee roasting systems are designed to process relatively large volumes of coffee, which is ideal for the coffee distributors and wholesale coffee roasters. However, developing a roasting receipt profile (i.e., a time versus temperature relationship) for a given grade or variety of green coffee bean can be expensive and time consuming due to the larger batch sizes that must be experimented with to obtain the desired roast profile. To control costs, many roasters are forced to buy a separate “sample” roaster, which is scaled in size for smaller sample batch quantities, but is a completely different coffee roaster from that being used to roast the larger commercial batch sizes. The disadvantage in using a separate sample roaster is that a sample roaster is not the same roaster that larger production batches will be roasted in. As a result, the correlation between the results of a sample roaster and a production roaster are always in question, because two different roasting machines are used. Thus, there remains a need for a fluid bed coffee roasting system capable of roasting both production batch sizes as well as sample batch sizes.
Aspects of the present invention fulfill these needs and provide further related advantages as described in the following summary.
It should be noted that the above background description includes information that may be useful in understanding aspects of the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.